A brief line from this comment indicates that the author of the cryonics-critical comment quoted here was perhaps not the one that deleted it.

You know what - I am rather glad my comment was deleted on less wrong - good reason for people not to post on there.

Was it deleted by a moderator?

Honestly, the decisive downvoting seemed to do the trick of hiding it from casual readers who don't want to see the long annoying rants. I don't think it was casting any doubt on the credibility of cryonics.

While it sounds like the author regrets posting it, I would think they should be allowed to delete it themselves.

Edit: Originally titled "Cryonics critical comment deleted?"

This is a thread to practice holding off on proposing solutions.

Rules:

1. Post your dilemma (i.e. problem, question, situation, etc.) as a top-level comment. You can always come back to edit this.
2. For the next 24 hours, replies in that thread can discuss only aspects of the problem, no solutions. (If something sounds too much like a solution, it gets downvoted.)
3. After the 24 hours have passed from the start of the thread, solutions may be proposed therein.

Note: Timezones for comments are in GMT (e.g. London), so you may need to use this to determine when 24 hours have passed in your local timezone.

What are the plausible scientific limits of molecular nanotechnology?

Richard Jones, author of Soft Machines has written an interesting critique of the room-temperature molecular nanomachinery propounded by Drexler:

Rupturing The Nanotech Rapture

If biology can produce a sophisticated nanotechnology based on soft materials like proteins and lipids, singularitarian thinking goes, then how much more powerful our synthetic nanotechnology would be if we could use strong, stiff materials, like diamond. And if biology can produce working motors and assemblers using just the random selections of Darwinian evolution, how much more powerful the devices could be if they were rationally designed using all the insights we've learned from macroscopic engineering.

But that reasoning fails to take into account the physical environment in which cell biology takes place, which has nothing in common with the macroscopic world of bridges, engines, and transmissions. In the domain of the cell, water behaves like thick molasses, not the free-flowing liquid that we are familiar with. This is a world dominated by the fluctuations of constant Brownian motion, in which components are ceaselessly bombarded by fast-moving water molecules and flex and stretch randomly. The van der Waals force, which attracts molecules to one another, dominates, causing things in close proximity to stick together. Clingiest of all are protein molecules, whose stickiness underlies a number of undesirable phenomena, such as the rejection of medical implants. What's to protect a nanobot assailed by particles glomming onto its surface and clogging up its gears?

The watery nanoscale environment of cell biology seems so hostile to engineering that the fact that biology works at all is almost hard to believe. But biology does work--and very well at that. The lack of rigidity, excessive stickiness, and constant random motion may seem like huge obstacles to be worked around, but biology is aided by its own design principles, which have evolved over billions of years to exploit those characteristics. That brutal combination of strong surface forces and random Brownian motion in fact propels the self-assembly of sophisticated structures, such as the sculpting of intricately folded protein molecules. The cellular environment that at first seems annoying--filled with squishy objects and the chaotic banging around of particles--is essential in the operation of molecular motors, where a change in a protein molecule's shape provides the power stroke to convert chemical energy to mechanical energy.

In the end, rather than ratifying the ”hard” nanomachine paradigm, cellular biology casts doubt on it. But even if that mechanical-engineering approach were to work in the body, there are several issues that, in my view, have been seriously underestimated by its proponents.

...

Put all these complications together and what they suggest, to me, is that the range of environments in which rigid nanomachines could operate, if they operate at all, would be quite limited. If, for example, such devices can function only at low temperatures and in a vacuum, their impact and economic importance would be virtually nil.

The entire article is definitely worth a read. Jones advocates more attention to "soft" nanotech, which is nanomachinery with similar design principles to biology -- the biomimetic approach -- as the most plausible means of making progress in nanotech.

As far as near-term room-temperature innovations, he seems to make a compelling case. However the claim that "If ... such devices can function only at low temperatures and in a vacuum, their impact and economic importance would be virtually nil" strikes me as questionable. It seems to me that atomic-precision nanotech could be used to create hard vacuums and more perfectly reflective surfaces, and hence bring the costs of cryogenics down considerably. Desktop factories using these conditions could still be feasible.

Furthermore, it bears mentioning that cryonics patients could still benefit from molecular machinery subject to such limitations, even if the machinery is not functional at anything remotely close to human body temperature. The necessity of a complete cellular-level rebuild is not a good excuse not to cryopreserve. As long as this kind of rebuild technology is physically plausible, there arguably remains an ethical imperative to cryopreserve patients facing the imminent prospect of decay.

In fact, this proposed limitation could hint at an alternative use for cryosuspension that is entirely separate from its present role as an ambulance to the future. It could perhaps turn out that there are forms of cellular surgery and repair which are only feasible at those temperatures, which are nonetheless necessary to combat aging and its complications. The people of the future might actually need to undergo routine periods of cryogenic nanosurgery in order to achieve robust rejuvenation. This would be a more pleasant prospect than cryonics in that it would be a proven technology at that point; and most likely the vitrification process could be improved sufficiently via soft nanotech to reduce the damage from cooling itself significantly.

Within the immortalist community, cryonics is the most pessimistic possible position. Consider the following superoptimistic alternative scenarios:

1. Uploading will be possible before I die.
2. Aging will be cured before I die.
3. They will be able to reanimate a whole mouse before I die, then I'll sign up.
4. I could get frozen in a freezer when I die, and they will eventually figure out how to reanimate me.
5. I could pickle my brain when I die, and they will eventually figure out how to reanimate me.
6. Friendly AI will cure aging and/or let me be uploaded before I die.

Cryonics -- perfusion and vitrification at LN2 temperatures under the best conditions possible -- is by far less optimistic than any of these. Of all the possible scenarios where you end up immortal, cryonics is the least optimistic. Cryonics can work even if there is no singularity or reversal tech for thousands of years into the future. It can work under the conditions of the slowest technological growth imaginable. All it assumes is that the organization (or its descendants) can survive long enough, technology doesn't go backwards (on average), and that cryopreservation of a technically sufficient nature can predate reanimation tech.

It doesn't even require the assumption that today's best possible vitrifications are good enough. See, it's entirely plausible that it's 100 years from now when they start being good enough, and 500 years later when they figure out how to reverse them. Perhaps today's population is doomed because of this. We don't know. But the fact that we don't know what exact point is good enough is sufficient to make this a worthwhile endeavor at as early of a point as possible. It doesn't require optimism -- it simply requires deliberate, rational action. The fact is that we are late for the party. In retrospect, we should have started preserving brains hundreds of years ago. Benjamin Franklin should have gone ahead and had himself immersed in alcohol.

There's a difference between having a fear and being immobilized by it. If you have a fear that cryonics won't work -- good for you! That's a perfectly rational fear. But if that fear immobilizes you and discourages you from taking action, you've lost the game. Worse than lost, you never played.

This is something of a response to Charles Platt's recent article on Cryoptimism: Part 1 Part 2

Cryonics scales very well. People who argue from the perspective that cryonics is costly are probably not aware of this fact. Even assuming you needed to come up with the lump sum all at once rather than steadily pay into life insurance, the fact is that most people would be able to afford it if most people wanted it. There are some basic physical reasons why this is the case.

So long as you keep the shape constant, for any given container the surface area is based on a square law while the volume is calculated as a cube law. For example with a simple cube shaped object, one side squared times 6 is the surface area; one side cubed is the volume. Spheres, domes, and cylinders are just more efficient variants on this theme. For any constant shape, if volume is multiplied by 1000, surface area only goes up by 100 times.

Surface area is where heat gains entry. Thus if you have a huge container holding cryogenic goods (humans in this case) it costs less per unit volume (human) than is the case with a smaller container that is equally well insulated. A way to understand why this works is to realize that you only have to insulate and cool the outside edge -- the inside does not collect any new heat. In short, by multiplying by a thousand patients, you can have a tenth of the thermal transfer to overcome per patient with no change in r-value.

But you aren't limited to using equal thickness of insulation. You can use thicker insulation, but get a much smaller proportional effect on total surface area when you use bigger container volumes. Imagine the difference between a marble sized freezer and a house-sized freezer. What happens when you add an extra foot of insulation to the surface of each? Surface area is impacted much as diameter is -- i.e. more significantly in the case of the smaller freezer than the larger one. The outer edge of the insulation is where it begins collecting heat. With a truly gigantic freezer, you could add an entire meter (or more) of insulation without it having a significant proportional impact on surface area, compared to how much surface area it already has. (This is one reason cheaper materials can be used to construct large tanks -- they can be applied in thicker layers.)

Another factor to take into account is that liquid nitrogen, the super-cheap coolant used by cryonics facilities around the world, is vastly cheaper (more than a factor of 10) when purchased in huge quantities of several tons. The scaling factors for storage tanks and high-capacity tanker trucks are a big part of the reason for this. CI has used bulk purchasing as a mechanism for getting their prices down to $100 per patient per year for their newer tanks. They are actually storing 3,000 gallons of the stuff and using it slowly over time, which implies there is a boiloff rate associated with the 3,000 gallon tank in addition to the tanks.

The conclusion I get from this is that there is a very strong self-interested case (as well as the altruistic case) to be made for the promotion of megascale cryonics towards the mainstream, as opposed to small independently run units for a few of us die-hard futurists. People who say they won't sign up for cost reasons may actually (if they are sincere) be reachable at a later date. To deal with such people's objections and make sure they remain reachable, it might be smart to get them to agree with some particular hypothetical price point at which they would feel it is justified. In large enough quantities, it is conceivable that indefinite storage costs would be as low as $50 per person, or 50 cents per year.

That is much cheaper than saving a life any other way. Of course there's still the risk that it might not work. However, given a sufficient chance of it working it could still be morally superior to other life saving strategies that cost more money. It also has inherent ecological advantages over other forms of life-saving in that it temporarily reduces the active population, giving the environment a chance to recover and green tech more time to take hold so that they can be supported sustainably and comfortably. And we might consider the advent of life-health extension in the future to be a reason to think  it a qualitatively better form of life-saving.

Note: This article only looks directly at cooling energy costs; construction and ongoing maintenance do not necessarily scale as dramatically. The same goes for stabilization (which I view as a separate though indispensable enterprise). Both of these do have obvious scaling factors however. Other issues to consider are defense and reliability. Given the large storage mass involved, preventing temperature fluctuations without being at the exact boiling temperature of LN2 is feasible; it could be both highly failsafe and use the ideal cryonics temperature of -135C rather than the -196C that LN2 boiloff as a temperature regulation mechanism requires. Feel free to raise further issues in the comments.